This invention relates to systems and methods for processing and collecting blood, blood constituents, or other suspensions of cellular material.
Today people routinely separate whole blood, usually by centrifugation, into its various therapeutic components, such as red blood cells, platelets, and plasma.
Conventional blood processing methods use durable centrifuge equipment in association with single use, sterile processing systems, typically made of plastic. The operator loads the disposable systems upon the centrifuge before processing and removes them afterwards.
Conventional blood centrifuges are of a size that does not permit easy transport between collection sites. Furthermore, loading and unloading operations can sometimes be time consuming and tedious.
In addition, a need exists for further improved systems and methods for collecting blood components in a way that lends itself to use in high volume, on line blood collection environments, where higher yields of critically needed cellular blood components, like plasma, red blood cells, and platelets, can be realized in reasonable short processing times.
The operational and performance demands upon such fluid processing systems become more complex and sophisticated, even as the demand for smaller and more portable systems intensifies. The need therefore exists for automated blood processing controllers that can gather and generate more detailed information and control signals to aid the operator in maximizing processing and separation efficiencies.
The invention provides systems and methods for processing blood and blood constituents that lend themselves to portable, flexible processing platforms equipped with straightforward and accurate control functions.
More particularly, the invention provides centralized, programmable, and integrated platforms to carry out diverse and coordinated pumping and valving functions, e.g., such as required for blood processing.
One aspect of the invention provides a cassette for directing fluid flow comprising a body and a valve chamber formed in the body. The valve chamber comprises a recessed wall forming a well and a valve port in the well. The cassette includes a valve seat, which extends below the recessed wall about the valve port. A flexible diaphragm on the valve chamber is responsive to an applied negative pressure for flexure out of the valve seat to open the valve port and responsive to an applied positive pressure for flexure into the valve seat to close the valve port. Sealing is accomplished by forcing the flexible diaphragm to flex into the recessed valve seat, to seal about the port.
In one embodiment, the valve port itself lays flush with the recessed wall.
In one embodiment, the cassette also includes at least one pump chamber formed in the body. The pump chamber comprises a recessed wall forming a well and a pump port in the well. A flexible diaphragm on the pump chamber is responsive to an applied negative pressure for outward flexure to draw fluid into the well through the pump port, the flexible diaphragm also responsive to an applied positive pressure for inward flexure to expel fluid from the well through the pump port.
Another aspect of the invention provides a cassette for directing fluid flow comprising a flow channel formed in the body and a pump chamber formed in the body and communicating with the flow channel. The pump chamber comprises a wall forming a well and a pump port in the well. A flexible diaphragm on the pump chamber is responsive to an applied negative pressure for outward flexure to draw fluid into the well through the pump port. The flexible diaphragm is also responsive to an applied positive pressure for inward flexure to expel fluid from the well through the pump port. The cassette also includes an interior cavity in the body communicating with the flow channel to trap air. A flexible diaphragm on the interior cavity is responsive to an applied positive pressure for inward flexure to expel fluid from the interior cavity.
Another aspect of the invention provides a cassette for directing fluid flow comprising a body and a pump chamber formed in the body comprising a recessed wall forming a well. A first pump port is located in the well, as is a second pump port, which is spaced from the first port. A flexible diaphragm on the pump chamber is responsive to an applied negative pressure for outward flexure to draw fluid into the well through one of the ports. The flexible diaphragm is also responsive to an applied positive pressure for inward flexure to expel fluid from the well through one of the ports. The cassette includes a race, which extends below the recessed wall between the first and second ports. The race establishes liquid flow continuity between the first and second ports, despite contact between the flexible diaphragm and recessed wall during inward flexure.
Other features and advantages of the inventions are set forth in the following specification and attached drawings.